4 Replies Latest reply on Nov 30, 2012 10:43 AM by Bill Kearns

    Linear Dynamic Drop Tests

    Bill Kearns
    Bill Kearns Nov 29, 2012 2:21 PM

      I've begun the process of using a Linear Dynamic setup to simulate an ISTA Drop Test (multiple drops). Does anyone have experience with something like this?  I'm looking to pick your brain regarding the setup.  Anybody who has extensive experience with Linear Dynamic studies can probably help, but drop test setups will be ideal.

       

      Thanks in advance!

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        • Re: Linear Dynamic Drop Tests
          Anthony Botting
          Anthony Botting Nov 29, 2012 7:19 PM (in response to Bill Kearns)

          From what I recall (in setup), you can tell it the traversal distance, or alternatively, the speed at impact. Next you tell it how long to integrate post impact. I believe it defaults to 25 milliseconds. You can tell it the direction of the gravity vector and the "virtual wall" angle relative to that. I believe that's about it. Does that help?

            • Re: Linear Dynamic Drop Tests
              Bill Kearns
              Bill Kearns Nov 30, 2012 7:49 AM (in response to Anthony Botting)

              Hi Anthony,

               

              I think you're referring to the standard 'Drop Test' setup that Simulation offers.  Unfortunately, SolidWorks only allows for one drop per set up with that option and I need to do multiple drops on the same pack while observing progressive damage.

                • Re: Linear Dynamic Drop Tests
                  Bill McEachern
                  Bill McEachern Nov 30, 2012 8:50 AM (in response to Bill Kearns)

                  Then your only option in a non-linear dynamic analysis. However, the damage accumulation part may or may not be able to be handled depending on the type of damage your are seeking to capture - you can bend some metal with  hardening but that is about it. In any case linear dynamics is not going to work if what you wrote is accurate.

                    • Re: Linear Dynamic Drop Tests
                      Bill Kearns
                      Bill Kearns Nov 30, 2012 10:43 AM (in response to Bill McEachern)

                      Thanks for your response, Bill.

                       

                      I'm still fairly new to Simulation, so please bear with me if I seem somewhat confused.  What I've been doing up to this point is adding forces to various faces/edges of my design to simulate the shock of a drop test. I've been using a time curve to simulate one drop after another and then looking at the results across all steps. The material I'm testing is molded paper pulp.  I've attatched an image of one of my results for you to see.

                       

                      CHAMFER CORNER DROP 2.JPG

                      We've compared our results to some live testing and our results are definitely in the ballpark.  By doing a time-driven simulation, I can look at the effects of each drop after it happens.  What do you think?